Various types of automated abrasion and polishing machinery have been developed to abrasively process articles of varying composition and configuration. In the semiconductor industry, for example, conventional chemical-mechanical planarization (CMP) machinery provides for automated planarization and polishing of semiconductor wafers. An example of an automatic wafer polishing apparatus is described in U.S. Pat. Nos. 5,643,044 and 5,791,969 issued to Lund, each of which is incorporated herein by reference in its entirety.
Conventional automated polishing machinery, such as that described in the above-identified patents, typically employs a computer-based control system to control the general polishing process. The servo control process used in such machinery is typically based on the shaft speed of a drive motor that drives a roll of abrasive material through the machinery. The shaft speed is compared to a programmed value, and a voltage or current supplied to the motor is adjusted by the servo control mechanism to equilibrate the sensed shaft speed with the programmed speed value.
Using this approach, only a indirect measure of abrasive roll speed may be obtained. Such an approach fails to account for a number of factors that can significantly affect the computation of the actual speed of the abrasive material relative to the wafer or article subject to polishing. Moreover, such conventional servoing approaches provide for only a limited degree of precision when attempting to position a particular region of abrasive material into contact with a given article during the polishing process. These and other limitations inherent in conventional automated polishing systems may have a profound negative impact on the ability to process and finish certain articles, such as semiconductor wafers, with a high level of precision.
Although conventional polishing approaches provide for some degree of automation, many of these approaches require human intervention at various steps. For example, an operator must typically verify, through manual means, that a particular type of abrasive product is appropriate for processing a particular type of article. An error made by the operator in this context will generally have deleterious results, typically resulting in damage to, or destruction of, costly articles and undesirable processing down-time. Other aspects of conventional polishing and abrasion processing methodologies are similarly limited in terms of automation, such as the use of partially automated or non-automated inventory systems, machine performance diagnostic systems, abrasive product/article tracking systems, and the like.
There exists a need for a system and method for abrasively processing articles that provide enhanced automation and data processing capabilities. There exists a particular need for an improved approach to controlling movement of an abrasive product relative to one or more articles during abrasion processing. There exists a further need for an integrated information system that provides for a variety of data acquisition and manipulation capabilities presently unavailable using conventional abrasion or polishing machinery. The present invention fulfills these and other needs.